Process of fibrating asphalt



Patented ca. .13, 525.

UNITED STATES ALAN" R. LUKENS,

PATENT OFFICE.-

PROCTISS FIIBRATING ASPHALT.

No Drawing.

To all whom it may concern.

' Be it known that I, ALAN R. Lumiere, a citizen of the United States,and a resident .of Wyoming, in the county of Hamilton and State of Ohio,have invented a certain new and useful Process for Fibrating Asphalt,

of which the following is a full, clear, and

- exact description.

My invention relates to improvements over the process developed by JamesC. Woodley, of incorporating fibers as set forth inhis patents, amongothers United States Patent, No, 1,156,122, dated October 12,

-- 1915. I It also relates to an improved prod- 15" not resulting fromthe process. I

I In the processes of Woodley, molten asphalt, vegetable fibers, in awet st-ate, and mineral ler, lar to a' bakers dough mixer, until aplastic or semi-granular state is. reached in which the asphalt has sochanged that upon ignitionof the material, no asphalt will-melt out,

' and in which the fibers are in complete suspension in the asphalt. Asdescribed by microscope the fibers of a piece of the \Voodley materialare in individual condition, but are chop edup into pieces. Thesepieces'are with difficulty visible to the naked eye, although they actto strengthen and toughen the asphalt very considerably, but they do notimpart near as much strength as if they were of greater length.

I find that by proceedin in a different way I can still gindivi'dua'izethe fibers,

thoroughly coat each fiber with asphalt or itumens of similar nature,and imother cor crate into the mix a large quantity of fine y dividedmineral matter, such as a dia--' tomaceous earth, without breaking upthe individual fibers into parts.

Of course, if a mineral matter of nonare kneaded in a mixer simi-.

Application flied January 4, 1928. Serial R0. 610,704.

abrasive nature substantially small in quantitles be used in the Woodleyprocess,

'the reduction of the fibers will not be so great. The real problemcomes when it is necessary, because of the uses to which the,

final material isto be put, to use a substance which has an abrasivequality very strongly marked, or where the mineral maton wromm onro,.assrenon To run nronennson comm, or nooxnnnn, 01110, A conrom'rrou or01110.

ter must be present in a predominating v quantity. I use in my process,by preference, a diatomaceous earth.

In processes which mvolve the steps of first dispersing bitumen in awatery aste of colloidal clay, and then mixing 1t with fibers, andfinally drawing out the'water from the clay, and thus reviving thebitumen, the limlts as to bituminous content ofthe final product arequite distinct. Such processes, as used in resin sizing, or asphaltSlZl-llg of paper are termed emulsification processes, and not only aremuch more limit;

ed as to result than my rocess, but in the nature of the action invoved, are about the converse of my process.

Furthermore a clay finely divided enough to act as an emulsifyingagentis usually not.

of a character suitable for acid resistance products, so that in rangeof minerals which may be used, my processis distinct over a fiber sizingprocess.

Known emulsification processes, while the may be carried on withincertain limits, an not be similar to the Woodley product, ed 1 have verydefinite limitations in the amount of bitumen whichcan be incorporated.into the product. In fact, in commercial uses of the mulsificationprocess, the usual practice results in a great excess of fibers overbitumen. My rocess gains the advantages in length of fi er of theemulsifying p ocesses, and still has a body high in bitumen and.

result in a product which may orma 7 hard because of the presence ofmineral matter, and may have other superior qua-ltities due to a chancefor selection of special -minerals for special uses.

Thus, myv process and product have advantages not obtainable in anyother manner, 'Ihe apparatus used with my process consists of mixers,similar to those used by bakers for mixing large batches of bread thepresence of water.

dough, and sufiicient heating devices to maintain asphaltin a moltencondition in The essential feature of my invention is that I mix, abitumen such as asphalt and mineral or earthy matter in-one beater, andthe same or a similar bitumen together with fiber in another, and thenmix the two resultant bodies together. I find that by properly mixingfinely divided mineral or earthy matter and asphalt withoutemulsification, I obtain a form of suspension in which each particle offinely divided filler is surrounded by a film of asphalt and is thusgreatly deprivedof its abrasive qualities. Then when both the fiber andfiller have been previously coated with bitumen they readily and quicklyblend together in a homogeneous mass without such final kneading ormixing, seriously pulverizing, or shortening the fiber. I'thus obtain amass which is stifi and strong yet is not brittle nor fragile.

Proceeding to described a typical commercial use of my invention, Ifirst determme what proportions sa of an asphalt, and mineral matter andher, which I desire in my final product. I then place in the first mixerthe least amount of the asphalt which will properly fully coat anddisperse the fiber, which action I have termed fibration,

and in another mixer I place the balance of the asphalt to be used forthe purpose of thoroughly coating the mineral or earthy matter.

While then maintaining heat under each mixer, into the firstmixer Iplace the desired amounts of fibers which may be in the form of scrappaper in a well moistened condition. As this mixer operates, it firstdisperses the fiber throughout the mass of asphalt and thereafterevaporates all of the water. Into the second mixer I place the desiredquantity of mineral or earthy matter, and operate it to knead up theproduct. Into the mineral or earthy matter mixer 1 add sufficient water,well short what would be an emulsifying quantity, yet suflicient tobreak down surface tensions topermit the mineral or earthy filler toenter quickly into full suspension.

As soon as the filler hasbeen uniformly dispersed I permit the water toevaporate as steam, addin no more water. After the water has thus eftthe mixer and thetezhperature has raised within the mixer sufficientlyto convert the mix into a smooth plastic mass, the action of the mixeris stopped and the contents of the fibrating mixer added. I A

The fibrating mi-xerha's been operated. all of this time, and, as taughtby W'oodley, the

action of the tackyasphalt on-th'e wet paper or fibers will be to; tearthe fibers' \up into. their original condition, and tolbre'ak-downsurface tensions at the same time suificiently that the fibers enterinto suspension in the asphalt, the Water not evaporating until thisweaves materially difi'erent from the Woodley roc- 1 ess, while thefibers are not materially ortened in length having been mixed only for ashort time in the presenceof the mineral or earthy filler, and thefiller beingat the time well coated, or --lubricated with the bitumenused.

As a material for the production of 'elec-" 'trolytic jars, which isreadily moldable, and has air suspension, sufficient to permitconsiderable compression in a die, the .material produced by my processis very superior. 'It can be made bothhard and tough, the fibers arethoroughly distributed, as is themineral matter, and the length of thefibers seems to increase their strength in holding themass I togetherwithout in any we afl'ectin the colloidal nature of the fina materi Itmay not be precise to designate as colloidal, the nature of thematerialwherein it differs over an asphalt which has boon-filledwith othermaterials, such as fiber andimineral matter, but in which the natureof'the asphalt has not undergone a change. This change, as has beenstated, is quite evident from the point of yiew'offusib lity, mymaterial being fully as infusible as. that of Woodleya By referring ,toasphalt diatomaceous earth and paper fiber, I" do not 1 wish tolimit myclaims that follow beyond" the usual range of e uivalents ofsuch'materials, nor do I wi to limit-my process. to a simultaneousaction ,of two mixers or any special instant for combining the two 7mixes or the particular manner of combining them or to the necessity ofimmediately making the final mixes before the first mixes become cold.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is: v 1. A process oi hardening and tougheninasphalt or the like bituminous bod whi'cfi consists in mixing "a bitumenanddivided matter having abrasive qualities,=' "1nde-' endently thereof,mixing a bitumen-and fibrous material, and final y placing the twomixedmasses together and them, whereby the abrasive qualityofthe matteragainst the fibrous material is reduced in said final mixing.

2. A process of hardening and toughening asphalt or the like bituminousbody, which consists in forming two mixes, by kneading together abitumen and finely divided matter having abrasive qualities andindependently kneading together bitumen and fibrous material in thepresence of water and heat, and then evaporating the water and finallymixing the two masses together produced by the in ependent kneading.

3. A process of hardening and toughening asphalt or the like bituminousbody, which consists in forming two-mixes by kneading together a bitumenand finely divided abrasive matter, and independently kneading togetherbitumen and fibrous material in the presence of heat and an agent tofirst form a film about the fibrous material which film is then replacedby the bitumen, and finally kneading together the mixtures so preparedALAN R. LUKENS.

